Shock absorber



June 3o, 1931;. J. A. KNIGHT 1,812,051

, SHOCK ABSORBER Fileamy e, 1928 2 sheets-sheet 1 June 30, 1931. I J. A KNlGHT 1,812,051

SHOCK ABSORBER Filed May 28, 1928 Y 2 Sheets-Sheet 2 rq J 29 30 fj? il f3 ff i 23 36 ZI IN VENTOR f 30 to allow yfor the viscosity Patented 'June 3f),Y 1931 r`JAMES A; xmennor minns'nx,` lNOVA SCOTIA, cnilvqiimfl,k f

- sIioeKABsonBEn- W y,Application filed kay 28,

This invention relates to shock absorbers asordinarily used 1n connectionwith automotive vehicle springsV and moreparticular- Y ly'to that type known as hydraulic con-1 '55 trollers, `'which are used topreventvthe 'sud-f den reboundof thesprings andwhichfconsists'mainl of a piston in 1a cylinderfilled withfoil, t e piston having vfree movement in one directionv and retarded movement' 1ny `10 the other. f

' The main objectI- ofL theinvention is to provide adevice of the' class mentioned:

` wherein the amount ofl control ofthe spring rebound will'Y vary in accordance with the 15 amount of pressure exerted Vby the same. In' other words, ifthe spring isfleXed slightly,

the reboundwilllbesmall and consequently lightcontrol is necessary. If, however, the

l means of a strap or pivoted rod', not shown... y In both types,tliev arm 15 is integral with spring is flexedjto! the limitglthe rebound will` be 'great and high control willl be re- Vquired. My devicekwill automatically ap-A ply the 4proportionate {amountof- *checking atall polntsaunder the' above@conditions.iy

i Another. objectof my invention is to prothe,;amount of cushioning required/u A further objectjof my invention is-to providemeans 'in ak shock. absorber of this class whereby-adjustment can e'asily be made ofthe liquid under varingtemperatures., l Y a.

yOtherobjects aswell as advantages'will become'apparent by following the descrip,I

tion hereinafteryin connection with the-Tap- '.35i lppendedjdrawings, `which show two i types of.

` vention.

shockV absorbers made `according to: my 'in- .In the drawings :v d l .i i i I Fgurel l1 is v av sectional elevation of'finy` 405 shockabsorber of the geared lever type;

f vFig'ure 2: is .a cross .sectional vvtop view taken online 22 ofvFigure l; y

Figure 3 is a fragmentaryy side .viewof the v absorber showing, the means' of -regulaf 45.' tionaccording to the viscosity ofthe liquid therein; j J, Fgure .45 isa cross Asectional top aview I taken on line l--All of Figure 1.,; Aand 'Figure 5 is a sectional yelevation ofl my vide adevice of-'this class which willfgi've piston.- rIn the design shown in7` Figure 5,l

Y tionis not positive,

192s. ser'ialm. 281,076. n z p l `Similar characters` of referencel'refer to similar' or v corresponding* parts throughout theviews. y

" BothV types'illustratedcomprise asimilar Y casing `6 lp'rovided with perforatedears'v for suitably mountingv the same. v The'casing is'clos'ed at its top b'y a cover 8 provided s l with agasket 9 to prevent leakage heldin place by cap screws 10; l portion 11 isenl'arged in'order -to yallowlthe of f oilV and The upper' i. Y

so mounting of they arm sha`ft`=12 sufficientlyf f distantfrom the vaxis of piston 13 to provide *Y the required leverage. Thelower partof v the casing is in the Vform offa cylinder v14 which receivesk piston 13. j'

- The casing is intended to the frame of the vehicleTheend =of"the arm 15 is connected to the spring or axle byI connection betweenshaft Y12 and the piston .is by means of ank eccentric lever 20, lwhich presses on the pistonhead. A As this conneca spring 21 is necessary'to raise the piston. VBothvthe lever '20'a'nd'segmentgear 18 are suitably'keyed to shaft 12 or rigidly held byfa. set screw 22, asshown. f I- The piston shown in Figure 1 consists fof a cylinderlike member'closed at vits bottom'y be mounted by a valve 24 which is held against 4-a'i-seat v 25 by a spring 26 mounted onfa stem 28 se``A cured to 'valve' 24, the spring being enclosed Vina cylindrical chamber 27- integral with they piston, Vas shown. A somewhat similar ar rangement is Aemployed in Figure 5.V exceptingthatthe valve is positioned fat'theftop of the piston-and thespring heldin theV head 29,.-4 The' inside of the'pistonis cupshaped sowasr 1.to receive' spring 21. Ports 30fare v provided` to allow the freepassage of fluid A hardened cap 31is mounted over the` head rofthe' piston on the upward movement;-

to forma bearing surface f'orlever20. y

HInFigure 1 the-.casinghas a groove 32 in i ce which a tongue 33, integral with rack 19, slides. This will keep the gear 18 and rack 19 in proper mesh and alinement.

On the downward movement of the piston, the liquid, usually oil, contained in the casing is forced through a by-pass consisting of a groove or slot 34 in the wall of the cylinder. The amount of resistance oflered in the said by-pass governs the amount of check. The means to cause said resistance consists in so mounting a plate 35 in groove 34 as to limit the passage of oil. The lower end of plate 35 plays in a space 36, while the upper end rests against a cam 37 and is held thereagai'nst by means of a spring 38 mounted in a bore 39, the spring being adjustable by means of a screw 40 threaded into bore 39. This bore is closed by a cap 4l threaded on the end thereof, which is in the form of a nipple 42 integral with he casing.

The shaft 43, carrying cam 37, has two diameters. The smaller diameter 44 is mounted in a perforation 23; and the larger diameter passes through the casing. W ith such a construction it will be apparent that the cam can be easily withdrawn from the casing. In order to adjust the face of the cam to regulate the position of plate 35, the outer end of shaft 43 is provided with polygonal faces received in ccngruous nipple 45 integral with the casing. To adjust the cam, the shaft is withdrawn until the faced portion is disengaged and re-inserted to obtain the required position. The outer face of shaft 43 may have iigures or other marks to indicate the actual position of the cam with relation to Jthe plate 35. Shaft 43 .is held in place by a cap 46 threaded over nipple 45. A small opening 47 at the top of groove 34 provides an outlet for the liquid that may leak back of plate 35 so as to allow the free movement of the latter. It will be understood that a fair fit is required between plate 35 and the walls of groove 34 to prevent excess leakage of oil.

The three adjustments above described render my device especially adaptable to any existing or operating conditions.

It will be noted that plate 35 is at an angle with the cylinder substantially from the point where it is held by spring 33. This causes the space for oil circulation to increase with the descent of the piston, and vice versa. When at the top of the cylinder, the piston practically closes the space. This will evidently give a great checking action to a vehicle spring flexed to a high degree but will allow a very light checking on quick jerks. The increasing allowance for the passage of oil 'as the piston descends will prevent hard riding as it will allow the spring to flex for cavities in the surface of the road.

In order to obtain the required space between the plate and the piston for a given load, the position of the piston will be de termined by proper adjustment of the connecting strap or rod, as the case may be. The angle of the plate, however, is adjust able by means of cam 37 so as to give the desired proportional checking. Owing to the higher viscosity of the oil in cold weather, more space will be required and this is obtained by regulating the cam to compensate accordingly.

Exceedingly sudden and extraordinary jerks which cause hard riding with the use of shock absorbers of the present type are oviated with my device by cushioning means which consist in allowing the plate to be depressed in whole or endwise as required jso as to afford a freer passage of oil. This desideratum is obtained by spring 38, which is mounted to press on plate 35 and is adjustable by a screw 40 to suit various vehicle springs and loads. rThis spring being located substantially at the top of the plate will give the desired proportional cushions ing at the lower end of the cylinder. The return of the piston to normal is obtained by 'the free passage ofthe oil through valve 24, common in the art.

`While I have described my invention strictly in accordance with the embodiment shown in the drawings, it must be understood that many departuresfrom the said drawings may be made without exceeding the spirit of my invention as covered by the scope of the following claims:

I claim as new and useful, and'desire to secure by Letters Patent:

l. Ina shock absorber' of the class described, a fluid containing cylinder, a piston mounted therein, a longitudinal slot in the side of the cylinder to form a by-pass communicating with opposite sides of said piston, a movable plate adjacent said slot, said plate forming a gradual incline to vary the areaV of the by-pass, and resilient -means to hold said plate in position.

2. In adevice of the class described, a fluid containing cylinder, a piston therein, a longitudinal slot in the side of said cylinder, an adjustable plate mounted in said slot,

means to adjust said plate to vary the area of the by-pass, and resilient means to maintain said plate in adjusted position. l

3. In a device of the class described, a fluid containing cylinder, a piston therein, a by-pass leading to both sides of the pis ton, an adjustable plate mounted adjacent said by-pass so as to incline towards the bot-v tom ofthe cylinder, meansvto adjust said plate to vary the area of the bypass, and resilient means to maintain said plate in adjusted position.

4. In a device of the class described, a fluid containing cylinder, a piston in said cylinder, a longitudinal slot in the side of said cylinder, a movable plate located adjacent said I io l of the by-pass will be greatest at the bottom of the cylinder, the ,area of the by-passy gradually diminishing upwardly,means for adjusting the plate within the slot to'vary the areaof the bypass, and resilient means carrying said gear, an Varm mounted on said shaft positioned outside vof saidcasing.

Y 9. A deviceA as stated. iniclaiin 7, having an outlet to allow the escape of oil that may a find its way back of the plate. Y Y

In .testimony of the foregoing, vI have hereto aiiixed my signature, this 16th day of May, 1928, at the city of Halifax, Nova Scotia, Canada. v v v AfKNIGHT.

mounted back of said .plate to maintain the same in ,adjusted vposition but to allow dis-Iy pressure of the placement upon excessive fluid in the cylinder. y

6. In a device of the class described, a fluid-containing cylinder, a piston mounted therein, a longitudinal slotj in theside `of said cylinder forming a by-pass coi'inecting` the opposite sides of the piston, a platey mounted in said slot so that. the cross area of the by-pass will be equal for a vportion of its length and gradually increasing down` wardly for the remaining portion thereof,

means for adjustingy the plate within the slot to vary the area of they 'by-pass, yand resilient means mountedback of said plate to maintain the same in adjusted positioiif 1 but to allow displacement` upon excessive pressure of the fluid in the cylinder.

7. In a device of the class described, a fluid-containing cylinder, a piston mounted to travel therein, a longitudinal recess in the side of said cylinder, a plate mounted to move laterally in said recess, .means to adjust thenormal position of said'plate, and'v y resilient l,means to allow'abnormal displace* ment of the plate'l on excessive rebounds.

- 8. A shock absorber, comprisingV a casing forming a cylinder at its lower 'end and an I enlarged chamber at the upper end,y a piston 1 travelling in the cylinder, a recess extendingv longitudinally of said cylinder, rforming a] I by-pass, anA inclined plate mounted to move laterally in said recess -so, as to form a lbypass of uniform area for-aportion.of the upper end of the cylinderfand of gradually increasing area down to theV bottom' of the cylinder, adjustableeccentric means to determinethe area of the by-pass, adjustable resilient ineans'mounted back of said plate to normally maintain the same in position but to give upon abnormal rebounds,ports throughV said cylinder, avalve to close said ports when the piston is moving Vdownward-y ly and to open them upon they upward-movei ment thereof so as to allow free passagef'of the fluid, a rack bar carried by said piston,

a segment gear in meshtherewith, a shaft Y Aiio` 

